Apparatus for sand blasting ceramic ware



April 2, 1940- J. A. BowER 2,195,810

APPARATUS FOR SAND BLASTING CERAMIC WARE Filed Nov. 11, 1937 INVEN TOR.a

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Patented Apr. 2, 1940 .53.;

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UNITED STATES APPARATUS FOR SAND BLASTING CERAMIC WARE James A. Bower,Chester, W. Va., assignor to The Taylor, Smith & Taylor Company, acorporation of .West Virginia A'pplicationNovember 11, 1937, Serial No.174,008

2 Claims.

My present invention relates to the handling v and treatment of ceramicware and pottery such 10 sides thereof to remove particles or impuritiesadhering to the surface and to prepare the surfaces for finishingoperations such as spraying them with glaze or enamel in a conventionalbooth. The sand blasting operation as hitherto carried out has beenfound to be far from satisfactory and in fact often did more harm thangood to the ware. This was in part due to the fact that there wasinsufficient control over the sand blasting and hence the force withwhich the sand impinged upon the ware surfaces was either too great ortoo little. Too great force not only v removed adhering particles butdamaged the ware itself and too little force failed to secure properpreparatory conditioning. Again, the use of auxiliary means, such aspins, carried by the conveyor for suspending the ware in a specialposition above the conveyor has been found to be difficult and notsusceptible of control. Therefore, while sand blasting has been used formany years and is recognized as a desirable and even a necessary step inmakingceramic ware or the like nevertheless the industry has not beenable to produce the desired results which the sand blast is intended toachieve.

It is, accordingly, one of the objects of my present invention toproduce a procedure and an apparatus whereby ceramic ware can beprepared for finishing operations by means of a sand blast without thehitherto unavoidable defects and disadvantages thereof.

Another object of my invention resides in a procedure and an apparatuswhereby ceramic ware canbe sand blasted without damage to the ware andwhile maintaining the sand blast under control, at the same time greatlyreducing maintenance thereof.

Another object resides in means for continu- .,ously sand blasting aseries of ceramic ware articles without interrupting thegeneral'procedure ordinarily employed in making such ware and incarrying out the sand blasting automatically with new and hithertounattainable ef-- ficiency and results. I

'A further object of my invention resides in means whereby ware can becontinuously subjected to a controlled sand blast disposed close to theware while the ware is supported directly on a series of spaced rollsand wherein the sandblast is applied simultaneously to both sides of theware in substantially vertical position and alignment.

Other and further objects and advantages reside in the variouscombinations, subcombinations and details of apparatus and procedurehereinafter described and claimed and in such other features as willeither be understood by those skilled in this art or will be apparent orpointed out hereinafter.

In the accompanying drawing wherein I have illustrated one form of thepresent invention and wherein like numerals designate correspondingparts throughout the various views:

Figure 1 is a side elevational view with parts broken away and insection of an apparatus for sand blasting ceramic ware in accordancewith the present invention.

Fig. 2 is an end elevational view partly in section of the apparatus ofFigure 1.

Fig. 3 is a plan view, partly diagrammatic, o the apparatus of Figures 1and 2.

Fig. 4 is a fragmentary elevation partly in section and with partsbroken away of the apparatus of Figure 1; and

Fig. 5 is a fragmentary perspective View of the sand boxes and hoseconnections of Fig. 1 on a larger scale. 7

Referring now to the drawing, a conveyor II] is shown as bringing wareII in aninverted position into the booth I2 wherein it is to be sandblasted. The conveyor lflis preferably made up of a plurality of spacednarrow rubber belts l3 which fit into recesses or grooves in the pulleysM mounted centrally on shafts I5. The conveyor l0 transports ware in thedirection of the arrow of Fig. 1 from a preceding operation which isusually a ware molding or forming operation and which is frequentlycarried out in sand molds, and hence the ware contains adheringparticles of sand. The ware, however, usually also has excess ceramicmaterial in some spots and may also have surface dirt, lint or otherimpurities which would interfere with the application of the glaze tothe ware.

To prepare the ware for glazing or enameling or for the application ofdesign it is transferred from the conveyor H] to a series of rotatingrubber covered rolls or shafts designated as a whole by the numeral l6.These consist of shafts I! extending through the back wall l8 of boothIZand carrying rubber tubes or coverings I9 011' their forward ends toprevent chipping, scratching or otherwise damaging the ware and theseare rotated in a counter-clockwise direction as viewed in Figure 1. Itwill be noted that there are seven such shafts projecting through theback wall of the booth and that two of themthe third and fourth from theleft in Fig. 1- are spaced further apart than the others. Shafts H areprovided with suitable bearings as diagrammatically shown at 20.

As shown more clearly in Fig. 3, each shaft ll has a pulley it near itsrear end by means of which the shafts are driven. Over each of pulleys25 a belt 22 passes which, like conveyor IE), is made up of a series ofspaced, narrow rubber belts either of round or of V-shaped section. Thebelt 22 is maintained in snug contact with all of the pulleys 25' bymeans of the four rolls 23 which, as shown in Fig. 4, cause said belt 22to be pressed into engagement with the seven pulleys 2i. The rubber belt22 beyond the pulleys 2i passes over pulleys 2 25 on the rear of shaftsi=5, and then over an idler roll 2? which maintains the proper tensionin the belt. As will be understood best from 3, pulley it on shaft ilies within booth i2 and pulley 24 on shaft is lies behind the booth.

After the ware H has traveled through the booth if it is againtransferred to a conveyor designated by the numeral 28 which is of thesame type and construction as the conveyor ill first described andcomprises two pulleys 29 mounted on shafts and provided with a number ofsurface grooves or rccesses for the reception of rubber belts 3b whichpass therearound. From conveyor 28 the were is transferred to anotherconveyor Iii fragrnentaiily shown in Figs. 1 and 3 and which is made upof wire cables 32 also passing around one pulley 29 but in groovesprovided between the grooves for the rubber belts 38, as will be seenfrom the lower portion of Fig. 3. It is this last conveyor, namelyconveyor 3!, which is the only one which is directly driven, all otherconveyors as well as the shafts described being driven from the wirecable conveyor as will be clear from the structure so far illustratedand described.

As the were passes through the booth on the rolls 6 it is subjected to acontrolled sand blast. will be understood from Figure l in particularthe sand is simultaneously projected against the top and bottom of theinverted ware, the sand blast from below passing between the spacebetween the third and fourth rolls I6 hereinabove referred to, and itwill be noted that the sand blast is projected against the waresubstantially vertically and from points relatively close to the ware.Each blast of sand is projected from between two metal plates 33 whichare connects together by bolt and nut assemblies 34 in such form as toprovide a chamber between the plates which tapers toward its dischargeend. Sand is irated to the inlet side of this tapered chamber 1-1 ough anumber of hoses or conduits the or end of each of which communicateswith a sturce of sand within the hopper 3'1.

As will be apparent, a series of sand boxes 38 is provided along thebottom of the hopper 3"! on each side thereof (five being shown in Fig.2, although any other suitable number may be utilized depending upon thesize and space requirenents and limitations), and one end of each hoseor conduit is secured thereto by couplings 39 it will be noted that thisend of the hose or conduit is beveled off at an angle at 46 so that thesand-continuously tending to drop down through the hopper into the sandboxes as it does-will tend to form conical piles of sand and thus causecontinuous feeding of sand to the tubes. As already pointed out the sandis caused to pass through the tubes 35 and between the plates 33 byaspiration which is produced by having the hoses or tubes 35 connectedinto or merging with air lines ll wherein compressed air or air underforced draft or pressure is being passed in the direction of the arrowsshown in Fig. 1. The air is supplied from the manifolds or supply lines42. Thus the air blast causes aspiration of sand in the manner of aninjector and thus enables sand to be impinged against the upper andlower surfaces of the ware, as shown.

It has been pointed out above that an important feature of the presentinvention resides in the control of the sand blasting operation or step.This control is provided in a number of different ways. First of all,the force of the air blast can be controlled and this directly affectsthe force with which the sand impinges against the were surfaces.Second, the distance of the plates 33 from the ware can be varied, thusfurther serving to affect the control in that the further the plates arefrom the were the less vigorous is the blasting operation and viceversa, and of course this distance may be correlated with the force ofthe air blast in order to produce the correct net resultant action uponthe ware. It is also possible to change the angle at which the air andsand blast strikes the ware and this may be used as a further control ifdesired, although I have found that an angle of approximately 90 degreesto the ware, as shown in Figure l, is the best for all ordinarypurposes. The spacing between plates 33 may also be adjusted so that theoutlet velocity of the sand can be reduced or so that the volume of sandmay be increased at the same or lower discharge pressure. By separatelyvalving the air inlets 4| it is further clear that a different force maybe used on one side of the ware than on the other and I have found thatsatisfactory operation is secured when the presthrough the hopper 31 viathe aperture 43 and then around within the booth l2 to the upper plates33 and while I have found that this is a desirable arrangement it is notintended to constitute a limitation upon this invention as otherspecific arrangements may be resorted to. The booth i2 is provided withsuitable windows or openings 44 for passage of the ware and conveyorsand the booth is preferably supported on legs 45 which constitute a partof the framework which supports the hopper and the other parts shown.

Thus in the production of glazed or enameled ware or other or similarceramic or vitreous articles, the same are subjected to a sand blastingoperation subsequent to the molding or forming operation and prior tothe spraying or glazing operation. This sand blasting is carried outsimultaneously upon both sides of the ware under controlled conditionssuch as to produce the optimum results and eliminate damage hithertofrequently done to ware by sand blasting. The sand blasting is undercontrol which can be varied for different types or sizes of ware orarticles and is preferably carried out at an angle of approximately 90degrees to the Ware generally with somewhat more force from above thanfrom it is therefore within the purview of my inven tion to vary thedetails thereof without departing from the scope or principles asdescribed above or set forth in the appended claims. Substitutions,modifications, additions and omissions within the foregoing descriptionare deemed to'be a part of my present invention. While the invention hasbeen particularly described in connection with the sand blasting ofceramic ware preparatory to glazing or enameling the same, it is not tobe understood as restricted solely thereto. It may be applied to otheruses Where metal or non-metal surfaces are to be sand blasted forcleaning, polishing or similar or analogous uses such as in sandblasting sheet metal or metal sheets prior to enameling, pickling orotherwise further treating the same.

Having thus described'my invention, what I claim as new and desire tosecure by Letters Patent is: Y

1. Apparatus for sand blasting ceramic ware preparatory to glazing thesame which comprises a booth-like enclosure having an opening in each ofits end walls, a series of stationary, rotatable, rubber-covered, spacedrolls projecting into the enclosure and disposed along the rear wallthereof, means external of said enclosure for driving the series ofrolls at the same speed, a delivery conveyor operating through one ofthe enclosure openings and terminating in ware transfer relationshipwtih one terminal roll of said series of rolls, a discharge conveyoroperating through the other enclosure opening and disposed in warereceiving relationship with the other terminal roll of said series ofrolls, a hopper below the rolls in the lower part of the enclosure, apair of spaced and converging metal plates disposed above and below saidseries of rolls in opposed relation to each other and conduit meansconnecting the chamber formed'betweeneach pair of plates with saidhopper and with a source of air under pressure.

Apparatus for sand blasting ceramic ware preparatory-to glazing the samewhich comprises a booth-lilreenclosure having an opening in each of itsend walls, a series of stationary, rotatable, rubbei covered, spacedrolls projecting into the enclosure and disposed along the rear wallthereof, means external of said enclosure for driving the series ofrolls atthe same speed, a delivery conveyor operating through one of theenclosure openings and terminating in ware transfer relationship withoneterminal roll of said series of rolls, a discharge conveyor operatingthrough the other enclosure opening and disposed in ware receivingrelationship with the other terminal roll of said series of rolls, ahopper below the rolls in the lower part of the enclosure, a pair ofspaced and converging metal plates disposed above and below saidseriesof rolls in opposed relation to each other and conduit means connee-tingthe chamber formed between each pair of plates with said hopper and witha source of air under pressure, said hopper being provided with sandboxes with which said conduit means com municate and said conduit meansincluding a pluralityof flexible hoses adapted to deliver a relativelylarge total amount of sand into the divergent ends of the chambersaforesaid.

JAMES A. BOWER.

